In this paper, a mathematical model of product upgradeability is proposed to provide a holistic measure at the design stage for a product’s potential to serve an extended use life and accommodate incremental changes/improvements of its functionality in the context of remanufacture. By using fuzzy set theory, the formulation of upgradeability model is focused on representing and measuring the effects of essential product technical factors. The ease-of-upgrade feature of a product is represented in terms of its technological, functional, physical, as well as structural fitness. Subsequently, three key indicators, namely compatibility to generational variety (CGV), fitness for extended utilisation (FEU), and life cycle oriented modularity (LOM) are developed to feature and evaluate the overall upgradeability potential of a product, providing insightful indications for any further improvement or redesign to base on.
